Friction devices for stenographic typewriter platens



July 24,1951 H M. VON DUYKE FRICTION DEVICES'FOR STENOGRAPHIICTYPEWRITER PLATENS Filed Oct. 28, 1947 Patented July 24, 1951 FRICTIONDEVICES FOR STENOGRAPHIC F TYPEWRITER PIIAEENS Harrison M. Von Duyke,Wilmington, Del., as-

signor to New Dictatype Company, Inc'orpo rated, Wilmington, Del.,acorporation'of Dela ware Application. October.28, 1947;,Serial No.782,473

This invention relates to friction devicesfor stenographic typewriterplatens, that is to. say, to devicesladapted to be used in connectionwith the paper. feed of stenographic typewriters, forthe purpose ofenhancing the frictional engagement between the paper and the platen,whereby the paper will be fed uniformly as the platen rotates with astep by step motion during the operation of themachine;

Heretofore, in typewriters, both of the ordinary-tr peand thestenographic type; various devices have been used for the purpose ofenhanc ing the frictional engagement betwecntthe paper and the platen,for the purpose of insuring-.the proper feed of the paper when theplaten is rotated. Such devices customarily comprise small rubber rolls,.variously located to impel the paper againstlthesurface of the platento causethe same to be fed in unison with the step by step rotation ofthe platen.

However, when such devices are made of r-ubher or the like, they becomehardened in the course of time and fail to function properly.

Furthermore, in typewriters of the stenographic type, in which theplaten is usually much shorter than in the ordinary typewriters, it ismore difficult to provide a satisfactory device of this character, whichwill be sure and positive in its action, and which will not wear ordeteriorate in the course of time.

Also, in stenographic typewriters, the paper is usually provided instrips, folded in what is known as a fan fold, so that variations in thegripping action occur as the paper-is fed over the platen, particularlywhere the creases occur.

The principal object of the present invention is to provide improvedmeans, particularly adaptable for use in stenographic typewriters, forenhancing the frictional engagement between the paper and the platen.

A further object of the invention is to provide, in a machine of thecharacter aforesaid, a device which will at all times maintain theproper frictional engagement between the platen and paper,notwithstanding irregularities which occur due to the difference inpaper thicknesses and when the creases in the paper strip pass over theplaten.

A further object of the invention is to provide, in a machine of thecharacter aforesaid, a device which continues to function and will notdeteriorate in the course of time, notwithstanding the fact that theperipheral travel of the paper over the platens of the stenographictypewriters is considerably more than that in the ordinary typewriters.

2 Claims. (C1. 197 -138),

The; nature. and characteristic features. of the presentlinvention willbe more readily understood fromthefollowing description, taken inconnection with the accompanying drawing forming part hereof, in which:

Eigure 1 is a perspective view of a deviceembodyinglthe main features ofthe present invention, the. same, being shown. in connection with platenof a stenographic typewriter;

Fig. Zisaverticalcentralsection thereof; and

Fig. a top orplan view of the principal portion of the device detached.

It should, of. course, be understood that the description and. drawingherein are illustrative merely, and that various modifications andchanges may be made in the structureclisclosed without departing fromthe spirit of "theinvention';

Referring to the drawing, there is therein shown the side plates 5 ofthe frame of a stenosuitable frame i2 comprising two side plates I3 anda spacing .bar it extendingtherebetween.

The side plates 13 of the frame 12 are pivotally mounted on a transverserod l5. The frame [2, and rollers 8 carried thereby, are positionedintermediate the ends of the platen 6 by means of split washers l6,which engage suitably located rooves IT in the rod I5.

The lower marginal edge Id of each of the side plates 13 of the frame I2is complemental in shape to the surface of the platen 6, and these edgesl3 are spaced a slight distance from said surfaceso that the side platesE3 of the frame I2 not only serve to support the rollers 8, but also actas guides for the front edge of the paper when the same is beinginitially fed therethrough.

The transverse rod i5 is mounted, at each end, with a more or less looseconnection, on the free end of a link I8. Each link It is pivotallymounted on one of the side plates 5 of the frame work of the machine bymeans of a pin l9.

On each side of the machine there is provided a coil spring 20, one endof which is connected to side plates of the frame work of the machineare so located with respect to the axis of the platen;

and the coil springs 20 are so positioned, that the grooved rollers 8will be pulled forwardly bythe springs 20 with a wedge like action sothat a proper and sufficient pressure will be exerted on the paperpassing over the platen 6 without unduly stressing the springs 2|].

By the foregoing arrangement there is provided to the platen, a framework carrying'said rollers; a transverse rod upon which said frame workis pivotally mounted, links in which said transverse rod is looselymounted at the ends thereof, and a coil spring on each side of themachine for impelling said rod forwardly, each of said coil springsbeing connected at one end to one end of said rod and at the other endto the frame work of the machine.

2. In a typewriter having a platen over which thepaper passes during theoperation of the machine, means for enhancing the frictional enga'gementof the paper with the platen comprising a pair of grooved metallicrollers bearing against a device for enhancing the frictionalengagement:

between the paper and the platen of a typewriter, which is particularlyadaptable for use on' stenographic typewriters, which will be durableand eflicient, and which will readily adjust itself to such variationsas occur from time to time, and particularly when the creases in thepaper pass over' the platen.

The connections between the transverse rod which supports the frictionrollers and the spring controlled arms upon which the ends of thetransverse rod are mounted are preferably of a loose character so thatthe friction rollers may readily adjust themselves to suchirregularities as occur in the operation of the machine.

I claim:

1. In a typewriter having a platen over which the paper passes duringthe operation of the machine, means for enhancing the frictionalengagement of the paper with the platen comprising a pair of grooved'metallic rollers bearing against and spaced circumferentially withrespect and spaced circumferentially with respect to theplaten, a framework carrying said rollers, a

' transverse rod upon which said frame work is pivotally mounted, linksfor supporting said. transverse rodat the ends thereof, and a coilREFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 833,840 Kunath Oct. 23, 19062,059,214 Dreher Nov. 3, 1936 2,319,273 Sterling May 18, 1943 Smith Apr.24, 1947

